The upside down (Modern)

Here, you just need a lot of mana and Torment of Hailfire for a win.

Your opponent will be able to afford losing life 6 times max. with torment of hailfire (unless he gains a lot of life somehow), so if he has, for exemple, 4 cards in hand and 3 or 4 permaments on the battlefield, you will need 14-15 mana to win, wich would mean you will need 7 lands and a crypt ghast, or 5 lands and 2 crypt ghast. Really easy to make in this deck.

If somehow he has a lot of permanents or a lot of life try to stay more time on the game with momentous fall, tendrils of corruption or just defending yourself with Korlash or the hydra (really strong big monsters in this deck btw), until you get 1 or 2 more lands (since every land will mean 2 or 3 more mana, allowing to repeat the hailfire process 2 or 3 times) or another crypt ghast. if you have more than 1 torment of hailfire in your hand just cast them on 2 consecutive turns for a win. Also you may just need to attack him if doing so you will be able to destroy some of his creatures or reduce his life total, smoothing the path for torment of hailfire. Crypt Ghast ability "extort" can help with that as well while helping you resist some turns.